/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --color-blue: #3B82F6;
    --color-green: #10B981;
    --color-yellow: #F59E0B;
    --color-red: #EF4444;
    --color-purple: #8B5CF6;
    --color-orange: #F97316;
    --color-gray-50: #F9FAFB;
    --color-gray-100: #F3F4F6;
    --color-gray-200: #E5E7EB;
    --color-gray-300: #D1D5DB;
    --color-gray-600: #4B5563;
    --color-gray-700: #374151;
    --color-gray-800: #1F2937;
    --color-gray-900: #111827;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--color-gray-800);
    line-height: 1.6;
    min-height: 100vh;
    padding: 2rem 1rem;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: white;
    border-radius: 24px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    overflow: hidden;
}

/* Header Styles */
.header {
    background: linear-gradient(135deg, var(--color-blue) 0%, #2563EB 100%);
    color: white;
    padding: 2rem;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.logo-section {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.logo {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 12px;
    padding: 0.5rem;
    backdrop-filter: blur(10px);
}

.header h1 {
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: 0.25rem;
}

.subtitle {
    font-size: 1rem;
    opacity: 0.9;
    font-weight: 400;
}

.header-meta {
    display: flex;
    gap: 0.5rem;
}

.badge {
    padding: 0.5rem 1rem;
    border-radius: 999px;
    font-size: 0.875rem;
    font-weight: 600;
}

.badge-blue {
    background: rgba(255, 255, 255, 0.2);
    color: white;
}

.badge-green {
    background: var(--color-green);
    color: white;
}

.badge-link {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    text-decoration: none;
    transition: all 0.3s ease;
}

.badge-link:hover {
    background: white;
    color: var(--color-blue);
}

/* Module Navigation - Tab Style */
.module-nav {
    background: var(--color-gray-50);
    padding: 0;
    display: flex;
    gap: 0;
    border-bottom: 3px solid var(--color-gray-200);
    overflow-x: auto;
    overflow-y: hidden;
    -webkit-overflow-scrolling: touch;
}

.module-nav a {
    padding: 1rem 1.5rem;
    text-decoration: none;
    color: var(--color-gray-600);
    font-weight: 600;
    font-size: 0.875rem;
    transition: all 0.3s ease;
    border-bottom: 3px solid transparent;
    white-space: nowrap;
    position: relative;
    background: transparent;
}

.module-nav a:hover {
    background: var(--color-gray-100);
    color: var(--color-gray-900);
    border-bottom-color: var(--color-gray-400);
}

.module-nav a.active {
    background: white;
    color: var(--color-blue);
    border-bottom-color: var(--color-blue);
    font-weight: 700;
}

/* Overview Section */
.overview {
    padding: 2rem;
    background: var(--color-gray-50);
}

.section-title {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--color-gray-900);
}

.overview-content p {
    font-size: 1.125rem;
    color: var(--color-gray-700);
    margin-bottom: 2rem;
    line-height: 1.8;
}

.overview-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
}

.stat-card {
    background: white;
    padding: 1.5rem;
    border-radius: 16px;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.stat-number {
    font-size: 2rem;
    font-weight: 800;
    color: var(--color-blue);
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--color-gray-600);
    font-weight: 500;
}

/* Workflow Stages */
.workflow-stages {
    padding: 3rem 2rem;
}

.stages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 1.5rem;
}

@media (max-width: 768px) {
    .stages-grid {
        grid-template-columns: 1fr;
    }
}

.stage-card {
    background: white;
    border-radius: 20px;
    padding: 2rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    border-left: 6px solid;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.stage-card::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 100px;
    height: 100px;
    opacity: 0.05;
    border-radius: 50%;
}

.stage-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.15);
}

.stage-blue {
    border-left-color: var(--color-blue);
}

.stage-blue::before {
    background: var(--color-blue);
}

.stage-green {
    border-left-color: var(--color-green);
}

.stage-green::before {
    background: var(--color-green);
}

.stage-yellow {
    border-left-color: var(--color-yellow);
}

.stage-yellow::before {
    background: var(--color-yellow);
}

.stage-red {
    border-left-color: var(--color-red);
}

.stage-red::before {
    background: var(--color-red);
}

.stage-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.stage-number {
    background: linear-gradient(135deg, var(--color-blue) 0%, #2563EB 100%);
    color: white;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.25rem;
}

.stage-green .stage-number {
    background: linear-gradient(135deg, var(--color-green) 0%, #059669 100%);
}

.stage-yellow .stage-number {
    background: linear-gradient(135deg, var(--color-yellow) 0%, #D97706 100%);
}

.stage-red .stage-number {
    background: linear-gradient(135deg, var(--color-red) 0%, #DC2626 100%);
}

.stage-header h3 {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--color-gray-900);
    line-height: 1.3;
    flex: 1;
}

.stage-icon {
    font-size: 3rem;
    text-align: center;
    margin: 1rem 0;
}

.stage-steps {
    list-style-position: inside;
    color: var(--color-gray-700);
    margin: 1.5rem 0;
}

.stage-steps li {
    padding: 0.5rem 0;
    font-size: 0.95rem;
    line-height: 1.6;
}

.stage-footer {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 1.5rem;
    padding-top: 1rem;
    border-top: 1px solid var(--color-gray-200);
}

.stage-tag {
    padding: 0.375rem 0.75rem;
    background: var(--color-gray-100);
    color: var(--color-gray-700);
    border-radius: 999px;
    font-size: 0.75rem;
    font-weight: 600;
}

/* System Logic Section */
.system-logic {
    padding: 3rem 2rem;
    background: var(--color-gray-50);
}

.logic-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.5rem;
}

.logic-card {
    background: white;
    padding: 2rem;
    border-radius: 16px;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
}

.logic-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.logic-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.logic-card h4 {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: 0.75rem;
}

.logic-card p {
    font-size: 0.95rem;
    color: var(--color-gray-600);
    line-height: 1.6;
}

/* UX Features Section */
.ux-features {
    padding: 3rem 2rem;
}

.features-container {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.feature-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1rem;
}

.feature-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    background: white;
    padding: 1.5rem;
    border-radius: 16px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
}

.feature-item:hover {
    transform: translateX(8px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
}

.feature-icon {
    font-size: 2rem;
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 12px;
    flex-shrink: 0;
}

.icon-green {
    background: rgba(16, 185, 129, 0.1);
    color: var(--color-green);
}

.icon-blue {
    background: rgba(59, 130, 246, 0.1);
    color: var(--color-blue);
}

.icon-purple {
    background: rgba(139, 92, 246, 0.1);
    color: var(--color-purple);
}

.icon-orange {
    background: rgba(249, 115, 22, 0.1);
    color: var(--color-orange);
}

.icon-red {
    background: rgba(239, 68, 68, 0.1);
    color: var(--color-red);
}

.feature-content h4 {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: 0.5rem;
}

.feature-content p {
    font-size: 0.95rem;
    color: var(--color-gray-600);
    line-height: 1.6;
}

/* Technical Requirements */
.technical-requirements {
    padding: 3rem 2rem;
    background: var(--color-gray-50);
}

.requirements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.requirement-card {
    background: white;
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
}

.requirement-card:hover {
    transform: scale(1.03);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.requirement-card h4 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: 1rem;
}

.requirement-card ul {
    list-style: none;
}

.requirement-card li {
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
    font-size: 0.95rem;
    color: var(--color-gray-700);
    line-height: 1.6;
}

.requirement-card li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--color-green);
    font-weight: 700;
}

/* Flow Diagram */
.flow-diagram {
    padding: 3rem 2rem;
}

.flow-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0;
    max-width: 600px;
    margin: 0 auto;
}

.flow-step {
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 100%;
}

.flow-box {
    background: white;
    padding: 1.5rem 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    text-align: center;
    width: 100%;
    max-width: 400px;
    transition: all 0.3s ease;
}

.flow-box:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.15);
}

.flow-box strong {
    display: block;
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: 0.5rem;
}

.flow-box span {
    font-size: 0.875rem;
    color: var(--color-gray-600);
}

.flow-start {
    background: linear-gradient(135deg, var(--color-green) 0%, #059669 100%);
}

.flow-start strong,
.flow-start span {
    color: white;
}

.flow-highlight {
    background: linear-gradient(135deg, var(--color-blue) 0%, #2563EB 100%);
}

.flow-highlight strong,
.flow-highlight span {
    color: white;
}

.flow-decision {
    background: linear-gradient(135deg, var(--color-yellow) 0%, #D97706 100%);
}

.flow-decision strong {
    color: white;
}

.flow-end {
    background: linear-gradient(135deg, var(--color-green) 0%, #059669 100%);
}

.flow-end strong,
.flow-end span {
    color: white;
}

.flow-arrow {
    font-size: 2rem;
    color: var(--color-gray-400);
    margin: 0.5rem 0;
}

.flow-split {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    width: 100%;
}

.flow-branch {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.flow-label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-gray-600);
    padding: 0.25rem 0.75rem;
    background: var(--color-gray-100);
    border-radius: 999px;
}

.flow-arrow-side {
    font-size: 1.5rem;
    color: var(--color-gray-400);
}

.flow-box-small {
    background: var(--color-gray-100);
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-gray-700);
}

/* Footer */
.footer {
    background: var(--color-gray-900);
    color: white;
    padding: 2rem;
    text-align: center;
}

.footer-content p {
    margin-bottom: 0.5rem;
}

.footer-note {
    font-size: 0.875rem;
    opacity: 0.7;
}

/* Responsive Design */
@media (max-width: 768px) {
    body {
        padding: 1rem;
    }

    .header h1 {
        font-size: 1.5rem;
    }

    .section-title {
        font-size: 1.5rem;
    }

    .logic-grid,
    .requirements-grid {
        grid-template-columns: 1fr;
    }

    .feature-row {
        grid-template-columns: 1fr;
    }

    .header-content {
        flex-direction: column;
        text-align: center;
    }

    .logo-section {
        flex-direction: column;
    }

    .flow-box {
        max-width: 100%;
    }
    
    .stage-header h3 {
        font-size: 1rem;
    }
}

/* iPhone and Small Mobile Devices (320px - 480px) */
@media (max-width: 480px) {
    /* Prevent iOS auto-zoom on focus */
    body {
        padding: 0.5rem;
        font-size: 16px; /* Minimum 16px to prevent iOS zoom */
    }
    
    .container {
        border-radius: 12px;
    }
    
    /* Header optimizations */
    .header {
        padding: 1rem;
    }
    
    .header h1 {
        font-size: 1.25rem;
    }
    
    .subtitle {
        font-size: 0.875rem;
    }
    
    .header-meta {
        flex-wrap: wrap;
        justify-content: center;
        gap: 0.25rem;
    }
    
    .badge {
        font-size: 0.75rem;
        padding: 0.375rem 0.75rem;
    }
    
    /* Tab navigation for mobile */
    .module-nav {
        padding: 0;
        gap: 0;
        -webkit-overflow-scrolling: touch;
        scrollbar-width: none; /* Firefox */
    }
    
    .module-nav::-webkit-scrollbar {
        display: none; /* Chrome/Safari */
    }
    
    .module-nav a {
        padding: 0.875rem 1rem;
        font-size: 0.8rem;
        min-width: fit-content;
    }
    
    /* Section spacing */
    .overview,
    .user-goals,
    .workflow-stages,
    .logic-section,
    .data-dependencies,
    .ui-elements,
    .ux-features,
    .technical-requirements,
    .flow-diagram {
        padding: 1.5rem 1rem;
    }
    
    .section-title {
        font-size: 1.25rem;
        margin-bottom: 1rem;
    }
    
    /* Overview stats */
    .overview-stats {
        grid-template-columns: repeat(2, 1fr);
        gap: 0.75rem;
    }
    
    .stat-card {
        padding: 1rem;
    }
    
    .stat-number {
        font-size: 1.5rem;
    }
    
    .stat-label {
        font-size: 0.75rem;
    }
    
    /* Goals grid */
    .goals-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .goal-card {
        padding: 1.25rem !important;
    }
    
    .goal-icon {
        font-size: 2.5rem;
    }
    
    .goal-card h4 {
        font-size: 1rem;
    }
    
    .goal-card p {
        font-size: 0.85rem !important;
    }
    
    /* Stage cards */
    .stages-grid {
        gap: 1rem;
    }
    
    .stage-card {
        padding: 1.25rem;
        min-width: unset;
    }
    
    .stage-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
    
    .stage-number {
        width: 36px;
        height: 36px;
        font-size: 1rem;
    }
    
    .stage-header h3 {
        font-size: 1rem;
        line-height: 1.3;
    }
    
    .stage-content h4 {
        font-size: 0.95rem;
    }
    
    .stage-content ol,
    .stage-content ul {
        font-size: 0.875rem;
        padding-left: 1.25rem;
    }
    
    /* Logic and dependency grids */
    .logic-grid,
    .dependencies-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .logic-card,
    .dependency-card {
        padding: 1.25rem !important;
    }
    
    .logic-icon {
        font-size: 2.5rem;
    }
    
    /* UI Elements */
    .ui-category {
        padding: 1.25rem !important;
    }
    
    .ui-category h4 {
        font-size: 1rem;
    }
    
    .ui-items {
        gap: 0.75rem;
    }
    
    .ui-item {
        padding: 0.75rem !important;
        font-size: 0.85rem;
    }
    
    /* UX Cards */
    .ux-cards {
        gap: 1rem;
    }
    
    .ux-card {
        padding: 1.25rem !important;
    }
    
    .ux-card h4 {
        font-size: 0.95rem !important;
    }
    
    .ux-card p {
        font-size: 0.8rem !important;
    }
    
    /* Feature items */
    .feature-row {
        gap: 0.75rem;
    }
    
    .feature-item {
        padding: 1rem;
        gap: 0.75rem;
    }
    
    .feature-icon {
        width: 40px;
        height: 40px;
        font-size: 1.5rem;
    }
    
    .feature-content h4 {
        font-size: 1rem;
    }
    
    .feature-content p {
        font-size: 0.85rem;
    }
    
    /* Requirements */
    .requirements-grid {
        gap: 1rem;
    }
    
    .requirement-card {
        padding: 1.25rem;
    }
    
    .requirement-card h4 {
        font-size: 1.1rem;
    }
    
    .requirement-card li {
        font-size: 0.85rem;
    }
    
    /* Flow diagram */
    .flow-box {
        padding: 1rem 1.25rem;
    }
    
    .flow-box strong {
        font-size: 1rem;
    }
    
    .flow-box span {
        font-size: 0.8rem;
    }
    
    .flow-arrow {
        font-size: 1.5rem;
    }
    
    /* Footer */
    .footer {
        padding: 1.5rem 1rem;
        font-size: 0.875rem;
    }
    
    /* Touch-friendly targets (minimum 44x44px) */
    button,
    a,
    .badge,
    .module-nav a {
        min-height: 44px;
        display: inline-flex;
        align-items: center;
        justify-content: center;
    }
    
    /* Disable hover effects on touch devices */
    @media (hover: none) {
        .stage-card:hover,
        .logic-card:hover,
        .feature-item:hover,
        .requirement-card:hover,
        .ux-card:hover {
            transform: none;
        }
    }
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.stage-card,
.logic-card,
.feature-item,
.requirement-card {
    animation: fadeIn 0.6s ease-out;
}

/* Smooth Scrolling */
html {
    scroll-behavior: smooth;
}

/* Consistent Spacing for User Goals (All Modules) */
.user-goals .goals-container {
    margin-top: 0;
}

.goal-card {
    padding: 1.75rem !important;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.goal-icon {
    margin-bottom: 0.75rem !important;
}

.goal-card h4 {
    margin-bottom: 0.5rem !important;
}

.goal-card p {
    font-size: 0.9rem !important;
    line-height: 1.5 !important;
    margin: 0 !important;
}

/* Consistent Spacing for Data Dependencies */
.dependency-card {
    padding: 1.75rem !important;
}

.dependency-card ul {
    margin: 0 !important;
}

.dependency-card li {
    padding: 0.4rem 0 !important;
    font-size: 0.875rem !important;
    line-height: 1.5 !important;
}

/* Consistent Spacing for UI Elements */
.ui-category {
    padding: 1.75rem !important;
}

.ui-item {
    padding: 1rem !important;
}

/* Consistent UX Cards Styling (All Modules) */
.ux-card {
    padding: 1.5rem !important;
    border-radius: 12px !important;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05) !important;
}

.ux-card:hover {
    transform: translateY(-3px) !important;
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.1) !important;
    border-left-width: 6px !important;
}

.ux-card h4 {
    font-size: 1rem !important;
    font-weight: 700 !important;
    margin-bottom: 0.5rem !important;
}

.ux-card p {
    font-size: 0.875rem !important;
    line-height: 1.5 !important;
    margin: 0 !important;
}